Edinburgh Research Explorer

The one-dimensional Lyα forest power spectrum from BOSS

Research output: Contribution to journalArticle

  • Nathalie Palanque-Delabrouille
  • Christophe Yèche
  • Arnaud Borde
  • Jean Marc Le Goff
  • Graziano Rossi
  • Matteo Viel
  • Éric Aubourg
  • Stephen Bailey
  • Julian Bautista
  • Michael Blomqvist
  • Adam Bolton
  • James S. Bolton
  • Nicolás G. Busca
  • Bill Carithers
  • Rupert A C Croft
  • Kyle S. Dawson
  • Timothée Delubac
  • Andreu Font-Ribera
  • Shirley Ho
  • David Kirkby
  • Khee Gan Lee
  • Daniel Margala
  • Jordi Miralda-Escudé
  • Demitri Muna
  • Adam D. Myers
  • Pasquier Noterdaeme
  • Isabelle Pâris
  • Patrick Petitjean
  • Matthew M. Pieri
  • James Rich
  • Emmanuel Rollinde
  • David J. Schlegel
  • Donald P. Schneider
  • Anže Slosar
  • David H. Weinberg

Related Edinburgh Organisations

Original languageEnglish
Article numberA85
JournalAstronomy & astrophysics
Publication statusPublished - 2013


We have developed two independent methods for measuring the one-dimensional power spectrum of the transmitted flux in the Lyman-α forest. The first method is based on a Fourier transform and the second on a maximum-likelihood estimator. The two methods are independent and have different systematic uncertainties. Determination of the noise level in the data spectra was subject to a new treatment, because of its significant impact on the derived power spectrum. We applied the two methods to 13 821 quasar spectra from SDSS-III/BOSS DR9 selected from a larger sample of over 60 000 spectra on the basis of their high quality, high signal-to-noise ratio (S/N), and good spectral resolution. The power spectra measured using either approach are in good agreement over all twelve redshift bins from 〈z〉 = 2.2 to 〈z〉 = 4.4, and scales from 0.001 km s-1 to 0.02 km s-1. We determined the methodological andinstrumental systematic uncertainties of our measurements. We provide a preliminary cosmological interpretation of our measurements using available hydrodynamical simulations. The improvement in precision over previously published results from SDSS is a factor 2-3 for constraints on relevant cosmological parameters. For a ΛCDM model and using a constraint on H0 that encompasses measurements based on the local distance ladder and on CMB anisotropies, we infer σ8 = 0.83 ± 0.03 and ns = 0.97 ± 0.02 based on Hi absorption in the range 2.1 < z < 3.7.

    Research areas

  • Cosmological parameters, Cosmology: Observations, Intergalactic medium, Large-scale structure of Universe

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